1. Field of the Invention
The present invention relates to an image input device used for reading images of a three-dimensional or planar object as digital data by a computer, and particularly relates to the interface control of such a device.
2. Description of the Related Art
For the purpose of transferring digitized image data, image input devices of this type in the prior art have used printer ports, serial ports, SCSI (Small Computer System Interface) ports, IO (Input/output) ports employing dedicated interface boards, and IO ports employing PC (Personal Computer) card interfaces.
In the above-described prior-art image input devices, the host device side has required a board dedicated to image input when transferring the read image data to the host device to which the image input device is connected. The image input device then transferred the image data to the host device using the dedicated interface, or transferred the data to the host device using a standard interface such as a SCSI. In such cases, the image input device required a control program corresponding to each of the various interfaces to respond to the operating system (hereinbelow abbreviated xe2x80x9cOSxe2x80x9d) of the host computer as an image input device.
An image input device using a SCSI interface described hereinabove having the object of increasing generality is disclosed in Japanese Patent Laid-open No. 109368/92. In this image input device, however, a control program for exchanging information with the host device must be produced for each host device. Japanese Patent Laid-open No. 18711/96 discloses an invention having the object of generalizing the interface portion in which a PC card is combined with a facsimile device. However, for the host device to recognize image input devices using a variety of interfaces as image input devices, a program dedicated to each interface must be incorporated in the host device.
An HDD (Hard Disk Drive) interface is another common example that enables connection with a device not incorporating a control program. However, using this interface in an image input device is not possible because, for example, connection of the image input device with the host device or OS can usually be realized only between devices of the same type, or due to the basic characteristic of an image input device, which is that the read data differ in each instance of use.
The object of the present invention is to provide an image input device that does not require consideration of the type of OS and hardware configuration of the host device, i.e., that does not require the task of incorporating a dedicated board or a control program dedicated to image input.
In the image input device of the present invention, tuple information, which is information that indicates to the host device the type of device upon connection to the host device, is information that indicates a PC card ATA (AT Attachment) or a memory card and is stored in ROM (Read Only Memory). As a result, the host device recognizes that the connected device is a memory card or a PC card ATA.
While an image reading construct is reading an image as digital data, an image reading circuit deactivates a control signal and makes first and second card detection signals high level, thereby causing the host device to judge that a PC card is not inserted. The image reading circuit then converts the digital data to image data of a file format that can be read by the host device and stores the result to RAM (Random Access Memory). When the image reading construct completes reading of the image, the image reading circuit activates the control signal and makes the first and second card detection signals low level, thereby causing the host device to judge that a PC card is inserted.
Accordingly, the read image data can be transferred to the host device using a program for controlling a PC card that is included in the OS of the host device.
According to another image input device of the present invention, when an interface control circuit is connected to the host device, it causes the host device to recognize the device as a removable device. Then, while the image reading construct is reading an image, the interface control circuit executes a response to the host device indicating that a disk medium is not inserted. The reading constrict converts the digital data to image data of a file format such as MS-DOS that can be read by the host device. The results are stored to RAM. When the image reading construct completes reading of the image, the interface control circuit executes a response to the host device indicating that the disk medium is inserted.
Accordingly, the read image data can be transferred to the host device using a program for controlling a removable device that is included in the OS of the host device.
As described hereinabove, the present invention enables an image input device to fetch the read image data without the necessity for providing a special control program in the host device, and a special control program for fetching image data therefore does not need to be developed or incorporated into the host device.
The above and other objects, features, and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings which illustrate examples of the present invention.